On Fri, 7 May 1999, Matthew Dillon wrote:

> :--- uthread_create.c 1999/03/23 05:07:55     1.12
> :+++ uthread_create.c 1999/05/06 15:27:33
> :@@ -42,6 +42,8 @@
> : #include "pthread_private.h"
> : #include "libc_private.h"
> : 
> :+static int next_tid = 1;
> :+
> : int
> : pthread_create(pthread_t * thread, const pthread_attr_t * attr,
> :            void *(*start_routine) (void *), void *arg)
> :@@ -87,6 +89,7 @@
> :             } else {
> :                     /* Initialise the thread structure: */
> :                     memset(new_thread, 0, sizeof(struct pthread));
> :+                    new_thread->tid = next_tid++;
> :
> :Doug Rabson                          Mail:  d...@nlsystems.com
> :Nonlinear Systems Ltd.                       Phone: +44 181 442 9037
> 
>     Hmmm.   tid is only an int and some programs which create and destroy
>     threads a lot are almost certainly going to overflow it.  4 billion
>     is not hard to reach.  This can result in duplicate tid's.

Didn't think of that.  It gets a bit ugly inside gdb since gdb needs a
single int to encode the pid and thread id.  I'm currently allowing 20
bits for the pid and 11 for the tid. Any ideas?

--
Doug Rabson                             Mail:  d...@nlsystems.com
Nonlinear Systems Ltd.                  Phone: +44 181 442 9037




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